The global art market grew 6% in 2018 to $67.4 billion in sales, according to economist Clare McAndrew’s report The Art Market 2019, released by Art Basel and UBS on Friday. That total makes 2018 the second-biggest year for the art market in the past decade, trailing only 2014 when sales totaled $68.2 billion.

The market is expanding into fewer hands, however, the report suggests. Despite the 6% growth, 57% of dealers saw their sales decline in 2018. This follows a trend over the past decade, during which the value of all sales has gone up 9%, while the number of artworks sold has gone down 9%.

In 2018, less than 5% of dealers accounted for 50% of the sector’s sales. Dealers in the two lowest brackets of annual turnover, sub-$250,000 and $250,000 to $500,000, saw sales decline by 18% and 4%, respectively, while dealers in the two highest brackets, $10 million to $50 million and $50 million-plus, saw their sales increase by 17% and 7%, respectively.

This uneven growth has been a subject of concern and conversation across the industry in the past year. Combined with anxieties over Brexit, the trade war between the United States and China, slowing global growth, and a sense of political uncertainty, it contributed to a general feeling of consternation within the industry about the immediate future.

Whereas, in 2017, 58% of dealers surveyed by McAndrew expected sales to go up the following year, this year’s report shows significantly lower confidence, with just 30% of dealers expecting their sales to increase in 2019. McAndrew said this apprehension reflects a general level of macroeconomic uncertainty to which smaller galleries and those that haven’t modernized their business practices are especially vulnerable.